Legal Question in Criminal Law in Nebraska

Re: Carrying Brass Knuckles

Not unless they are in plain view. If they are in a pocket, or carrying scabbard etc and cannot be recognized instantly for what they are, they are a concealed weapon, and subject to criminal penalty.

Striking someone with brass knuckles is a second degree assault unless done in self defense, while generally striking someone with a hand or foot is a third degree assault. Second degree assault is a felony and third degree assault is a misdemeanor.